Adobe Web Tech Curriculum

Unit 10: Intermediate Graphics

Lesson 10.1: More on Layers

Managing Layers

  1. The Layers Palette
  2. Stacking Order
  3. Groups
  4. Rasterizing Layers
  5. Linking Layers
  6. Locking Layers
  7. Flattening Layers

The Layers Palette

Figure 10.1-5 shows the Layers Palette as originally presented in the Layers Basics section of the Photoshop Basics lesson. The following features were introduced in that lesson:

  • Show/Hide Layer Photoshop Show layer button — This icon is a toggle that controls whether the layer is visible or not. The eye icon indicates the layer is visible.
  • Link Layers Icon Photoshop Active Layer button — This button links two or more layers. Linked layers can be moved, etc. together as one group or unit.
  • Add a Layer Style Photoshop Layer Style button — This button opens a drop-down list of layer styles that can be applied to that layer, including drop shadows, bevels, etc.
  • Add a Layer Mask Photoshop Add a Layer Mask button — This button creates a new layer mask.
  • Create New Fill or Adjustment Layer Photoshop New Fill button — This button opens a drop-down list of fills that can be applied to that layer, including color, gradients, etc.
  • Create a New Group Photoshop New Group button — This button creates a new group.
  • Create New Layer Photoshop New Layer button — This button creates a new empty layer. Text automatically creates a new layer, without having to use the Create New Layer button.
  • Delete Layer Photoshop Delete Layer button — This button deletes the selected layer from the Layers Palette.
 Photoshop Layers Palette

Figure 10.1-5: Photoshop's Layers Palette

Stacking Order

The stacking order of the layers in the Layers Palette is important because it determines which layer appears to be "on top," second, third, etc. in the finished image. The examples below illustrate the impact stacking order can have on an image. Figure 10.1-6 shows the stacking order of the layers for the image in Figure 10.1-7. Note the Shape 2 layer (the blue rectangle) is above the Shape 1 layer (the red ellipse) in the stacking order of the image in the Layers Palette shown in Figure 10.1-6. Figure 10.1-7 shows the corresponding image, i.e., a blue square on top of a red ellipse.

Stacking order of figure 10.1-7

Figure 10.1-6: Photoshop's Stacking Order for the Image in Figure 10.1-7

 Image of blue square on top of red ellipse

Figure 10.1-7: Sample Image

The next set of figures illustrate what happens to an image when the stacking order is changed. Figure 10.1-8 shows the stacking order of the layers for the image in Figure 10.1-9. Notice that the Shape 1 layer (the red ellipse) is now at the top of the stacking order and as a result appears in front of the blue rectangle in Figure 10.1-9.

Stacking order of figure 10.1-9

Figure 10.1-8: Photoshop's Stacking Order for the Image in Figure 10.1-9

 Image of red ellipse on top of blue square

Figure 10.1-9: Sample Image

To change the stacking order of layers within an image, follow these steps:

  1. Select a layer (or layer set) and drag it to a new location within the stacking order. You should be able to see the outline of the layer box move as you drag the layer to its new location.
  2. Release the mouse when the layer is in its new location.

Demonstration or Practice Activity

  1. Open the Photoshop document created in the previous activity.
  2. Make sure the shapes overlap each other a little.
  3. Move the stacking order of the three different images to see the impact stacking order has on the image.
  4. Save this file for use in the next activity.

Groups

Individual layers can be grouped into groups. Groups are used to assist with the organization of multiple layers within an image. One advantage to establishing groups is that individual layers within the group can be moved together within the palette. Once a group has been created, the set can be toggled (using the toggle arrow) so that each layer within the group appears separately or only the group name appears in the Layers Palette.

Figure 10.1-10 shows the Layers Palette with two individual text layers grouped into one layer set called "Text."

To create a group, follow these steps:

  1. Click the Create a New Group button Photoshop Layer Set button located at the bottom of the Layers Palette.
  2. Drag individual layers from the Layers Palette onto the new group.

Note: A new layer set can also be created by using the following menu steps:

Layer > New > Group

 Photoshop Layer Set

Figure 10.1-10: Photoshop's Layers Palette with "Text" Layer Set

Demonstration or Practice Activity

  1. Open the file saved in the previous activity.
  2. Add three text layers describing the color and shape of the objects drawn (e.g., "blue square").
  3. Move the three objects drawn in previous activities so they are no longer overlapping.
  4. Move each text layer just under the object it describes.
  5. Create three groups, one for each shape/text combination (e.g., "blue square set").
  6. Move each text layer to the appropriate Group.
  7. Try moving the shape layers to the appropriate group. What happens? You'll learn how to move the shape layers to the Group next.

Rasterizing Layers

It may be necessary to rasterize particular layers within your image. Photoshop doesn't allow paint tools or filters to be used on layers with vector information such as shape layers. However, it does allow layers with vector information to be rasterized and then modified.

Figure 10.1-11 shows a shape layer (red rectangle) within the Layers Palette. Notice how the shape layer, which has vector information, looks different from a generic layer.

An individual layer can be rasterized or multiple layers can be rasterized simultaneously. To rasterize layers, follow the steps below:

 Photoshop Layers Palette showing linked layers

Figure 10.1-11: Photoshop Layers Palette with Shape Layer
  1. Select the layer or layers to be rasterized.
  2. Choose the appropriate sequence of menu steps:

    • Layer > Rasterize > Type

    • Layer > Rasterize > Shape

    • Layer > Rasterize > Fill Content

    • Layer > Rasterize >  Vector Mask

    • Layer > Rasterize > Smart Object

    • Layer > Rasterize > Layer

    • Layer > Rasterize >  All Layers

Once the layer is rasterized, the Layers Palette will show the layer as it does other generic layers.

Demonstration or Practice Activity

  1. Rasterize the shape layers of the previous activity.
  2. Move the newly rasterized layers to the appropriate Layer Set.

Linking Layers

Linking layers or groups allows you to modify the selected layer and have the modifications affect the layers linked to it. To link layers within the Layers Palette, follow these steps:

  1. Select the layers or groups to be linked.
  2. Click the Link Layers icon. A chain link will appear to the right of the linked layer's thumbnail as shown in the Shape 1 row of Figure 10.1-12.
 Photoshop Layers Palette showing linked layers

Figure 10.1-12: Photoshop Layers Palette with Linked Layers

To remove the link between layers, click on the chain link icon of the linked layers.

Locking Layers

Individual layers of an image can be locked to protect that layer's content from being edited. Photoshop provides several levels of locks. The layer lock options Photoshop Layer Lock options are found just above the layer thumbnail area of the Layers Palette.

  • Lock Transparent Pixels Photoshop Layers Palette Lock Transparent Pixels Icon — This locks all transparent pixels within the layer and only allows colored pixels to change when tools or filters are used.
  • Lock Image Pixels Photoshop Layers Palette Lock Image Pixels Icon — This locks colored pixels within the layer and only allows transparent pixels to change when tools or filters are used.
  • Lock Position Photoshop Layers Palette Lock Position Icon — This locks the location (position) of the layer.
  • Lock All Photoshop Layers Palette Lock All Icon — This prevents any changes to the layer content; however, the layer's stacking order can still be changed.

Flattening Layers

Images saved for use on the Web, such as GIF and JPEG images, do not include layer information; therefore, images created in Photoshop and saved as GIF or JPEG must have the image layers flattened. Flattening an image basically merges all the layers into the background layer, which can dramatically reduce the overall file size. Typically, an image isn't flattened until it is in its final form, because, once an image is flattened, you lose control over the individual layers.

To flatten layers into the background layer, follow these menu steps:

Layers > Flatten Image

In addition to flattening all the layers of an image, Photoshop provides a way to merge selected layers. This can be handy if you aren't ready to flatten the entire image, but feel comfortable combining two or more layers into one. There are several options available within the Layers Palette Menu for dealing with merging layers. The available options will change, based on layer specifics:

  • Merge Visible combines all visible layers. Make sure the individual layers to be merged are all visible within the Layers Palette.
  • Merge Linked combines the selected layer and any layers linked to it.
  • Merge Down combines all layers behind (below) the selected layer.
  • Merge Layer Set combines layers within a layer set.
  • Merge Layers combines selected layers.

Demonstration or Practice Activity

  1. Using the file from the previous activities, add several additional objects, each on its own layer.
  2. Practice using the various flattening and merging options on the objects and layers within your document.
  3. Describe in detail the processes you go through and the outcomes.

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